The actuation of control devices having mechanically displaceable actuator members, using pressure switch fluid actuator devices of the type noted above, is a common practice. However, such devices are not always capable of reliably providing the force required, e.g. to simultaneously actuate a plurality of certain known types of control action devices, i.e. momentary action electrical switches, electrical snap switches, optical shutters fiber optic switches, fluid control valves and the like, particularly when arranged in side-by-side arrays. Also, such fluid actuator devices are not entirely suitable for use in actuating snap switches of higher electrical ratings; this type of switch being relatively heavily spring loaded and requiring a relatively high applied force in order to be actuated. This is particularly the case when an alternate action mechanism is employed with a multiplicity of control devices, due to the increased friction and inertia of the system.